As an active matrix type liquid crystal display device, one comprising a display part using amorphous silicon in TFT, and an IC for an external driving circuit; an integrated type comprising a display part using polycrystalline silicon by a solid phase growing method in TFT, and a driving circuit (as described in JP-A-6-242433); and an integrated type comprising a display part using polycrystalline silicon having been subjected to excimer laser annealing in TFT, and a driving circuit (as described in JP-A-7-131030) have been known.
However, although the conventional amorphous silicon TFT exhibits good productivity, the electron mobility is as low as about from 0.5 to 1.0 cm.sup.2 /v.multidot.sec, and a MOS TFT of p-channel (hereinafter referred to as a pMOS TFT) cannot be produced. Therefore, because a peripheral driving part using a pMOS TFT cannot be formed on the same glass substrate as one, on which a display part is formed, a driver IC is externally attached as mounted by a TAB method, and thus the production cost is difficult to be reduced. There is also a limit to increase the minuteness because of the same reasons. Furthermore, because the electron mobility is as low as about from 0.5 to 1.0 cm.sup.2 /v.multidot.sec, a sufficient on electric current cannot be ensured, and in the case where it is used as a display part, the size of the transistor necessarily becomes large, and thus it is disadvantageous for increasing the opening ration of a pixel.
Because the conventional polycrystalline silicon TFT has an electron mobility of from 70 to 100 cm.sup.2 /v.multidot.sec and can cope with high minuteness, an LCD (liquid crystal display device) of a driving circuit integrated type using a polycrystalline silicon TFT receives attention. However, in the case of a large LCD of 15 inches or larger, because the electron mobility of polycrystalline silicon is from 70 to 100 cm.sup.2 /v.multidot.sec, the driving performance becomes insufficient, and as a result, an IC for an external driving circuit becomes necessary.
In the case of the conventional TFT using polycrystalline silicon formed in to a film by a solid phase growing method, because the annealing at 600.degree. C. or more for several tens hours and the formation of gate SiO.sub.2 by thermal oxidation at about 1,000.degree. C., it is necessary to employ an apparatus for producing a semiconductor. Therefore, there is a limit in size of a wafer of from 8 to 12 inches, and furthermore quartz glass, which is of high heat resistance but expensive, is necessarily employed, which bars reduction in production cost. Therefore, the usage thereof is limited to an EVF and a data/AV projector.
The conventional polycrystalline silicon TFT by excimer laser annealing involves many problems, for example, in stability of excimer laser output, productivity, increase in apparatus cost due to a large-scale apparatus, and reduction in yield and product quality.
Particularly, in the case of a large-scale glass substrate, such as 1 m square, the problems are enhanced, and increase in performance and quality, and reduction in cost become difficult.